At Savatthi. “Bhikkhus, develop concentration. A bhikkhu who is concentrated understands things as they really are.

“And what does he understand as it really is? He understands as it really is: ‘This is suffering.’ He understands as it really is: ‘This is the origin of suffering.’ He understands as it really is: ‘This is the cessation of suffering.’ He understands as it really is: ‘This is the way leading to the cessation of suffering.’

“Bhikkhus, develop concentration. A bhikkhu who is concentrated understands things as they really are.

“Therefore, bhikkhus, an exertion should be made to understand: ‘This is suffering.’ An exertion should be made to understand: ‘This is the origin of suffering.’ An exertion should be made to understand: ‘This is the cessation of suffering.’ An exertion should be made to understand: ‘This is the way leading to the cessation of suffering.’”

The Buddha's words/Samādhisutta SN 56.1. Translated by Bhikkhu Bodhi